<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0px;
            padding: 0px;
        }
        .meun{
            width: 300px;
            height: 50px;
            background-color: brown;
            text-align: center;
            
            
            
        }
        .meun:hover .caidan{
            position: relative;
            top: 0px;
        }
        span{
            color: white;
            font-size: 20px;
            line-height: 50px;
            
        }
        .caidan{
            width: 300px;
            height: 300px;
            background-color: rgb(165, 98, 98);
            position: relative;
            top: -300px;
            z-index: -1;
            transition: 0.5s;
        }
        .item{
            display: flex;
            width: 600px;
            
        }
        .int{
            width: 300px;
            background-color: rgb(165, 98, 98);
        }
        .ins{
            background-color: aqua;
            transition: 0.5s;
            width: 300px;
            position: relative;
            left: -300px;
            z-index: -1;
        }
        .item:hover .ins{
            position: relative;
            left: 0;
        }
    </style>
</head>
<body>
    <div class="meun">
        <span>菜单选项</span>
        <div class="caidan">
            <div class="item">
                <div class="int">
                <span>选项1</span>
                </div>
                <div id="ji">
                <div class="ins"><span>子选项1</span></div>
                <div class="ins"><span>子选项1</span></div>
                <div class="ins"><span>子选项1</span></div>
                </div>
                </div>
            </div>
            <div class="item"><span>选项</span></div>
            <div class="item"><span>选项</span></div>
            <div class="item"><span>选项</span></div>
            <div class="item"><span>选项</span></div>
            <div class="item"><span>选项</span></div>
        </div>
        
    </div>
    
</body>
</html>